Bidirectional adjusting geometric throat for rocket-based combined cycle engine

Abstract

The invention discloses a two-way adjusting geometric throat for a rocket-based combined cycle engine, which comprises a geometric throat section which is of a shell structure with left, right and upper openings, and a throat plugging block which is arranged at the upper opening of the geometric throat section, the shape of a flow channel in the geometric throat section is adjusted by adjusting the posture of the throat plugging block; each rotating cylinder of the switching mechanism penetrates through the shell of the geometric throat section and clamps or loosens the throat plugging block; the switching mechanism enables the throat plugging block to rotate with the different rotating cylinders as axes by adjusting the telescopic states of the rotating cylinders so as to change the posture of the throat plugging block, and then an internal flow channel of the geometric throat section is switched between contraction and expansion. The geometric throat device solves the problem that full-speed-domain matching work of a combustion chamber of a combined cycle engine and different incoming flows cannot be achieved due to the fact that an existing geometric throat device with single rotation actuation cannot meet the variable structure requirement of an injection mode.

Description

Technical Field

[0001] The invention belongs to the technical field of combined cycle engines and relates to a bidirectionally adjustable geometric throat for a rocket-based combined cycle engine. Background Art

[0002] To achieve coordinated matching of combined cycle engines across the full speed range, selecting appropriate matching technologies to balance the mission requirements of different modes is a key step in improving combined cycle engine performance. Due to the wide operating speed range of combined cycle engines, a fixed combustion chamber configuration makes it difficult to achieve matching between intake and combustion structures over such a wide range. Therefore, a variable structure combustion chamber is one of the effective strategies for achieving matching across the full speed range of combined cycle engines.

[0003] Currently, geometric throat adjustment technology within the variable structure combustion chamber strategy is an effective means of matching the intake and combustion structures in the subcombustion mode of combined cycle engines. Specifically, in response to varying incoming flow conditions, the geometric throat device at the end of the combustion chamber is actuated to change the combustion chamber's expansion ratio, forming a convergent-divergent flow path. This fully matches the combustion chamber expansion ratio with the incoming flow conditions, thereby improving engine performance. However, for the ejection mode, the incoming airflow conditions are relatively low, and the flow path is completely subsonic, which cannot meet the requirements of the ejection mode. Furthermore, the convergent-divergent flow path in the subcombustion mode would further reduce the gas flow rate. Therefore, the convergent-divergent flow path formed by the geometric throat adjustment method in the subcombustion mode does not conform to the flow characteristics of the ejection mode. Furthermore, it increases resistance and occupies a portion of the combustion heat release interval, significantly reducing the performance of the ejection mode.

[0004] In summary, the previous single-rotational geometric throat device cannot meet the variable structure requirements of the ejection mode, and therefore cannot achieve full-speed domain matching of the combined cycle engine combustion chamber and different incoming flows. Summary of the Invention

[0005] In order to achieve the above-mentioned objectives, the present invention provides a bidirectionally adjustable geometric throat for a rocket-based combined cycle engine, which solves the problem that the existing single-rotational geometric throat device cannot meet the variable structure requirements of the ejection mode, thereby making it impossible to achieve full-speed domain matching between the combined cycle engine combustion chamber and different incoming flows.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is a bidirectionally adjustable geometric throat for a rocket-based combined cycle engine, comprising:

[0007] The geometric throat section is a shell structure with openings on the left, right, and top. The left opening of the geometric throat section is fixedly connected to the combustion chamber section, and the right opening of the geometric throat section is fixedly connected to the tail nozzle section. The interior of the shell of the geometric throat section is the gas flow path of the engine combustion chamber;

[0008] Throat block, which is set at the opening above the geometric throat section. By adjusting the posture of the throat block, the flow channel shape inside the geometric throat section can be adjusted;

[0009] The switching mechanism is fixed on the geometric throat section. The rotating cylinders of the switching mechanism pass through the shell of the geometric throat section and clamp or release the throat block. The switching mechanism adjusts the telescopic state of each rotating cylinder so that the throat block rotates with different rotating cylinders as the axis to change the posture of the throat block, thereby switching the internal flow channel of the geometric throat section between contraction and expansion.

[0010] The beneficial effects of the present invention are:

[0011] The present invention meets the demand for changing the optimal profile of the flow channel in the combustion chamber under different incoming flow conditions, thereby realizing the dynamic matching and balance between the intake and combustion chamber profiles in the full-speed range of the RBCC engine; through different actuation strategies, the control of the combustion chamber end profile is completed, and the working capacity of the gas is fully exerted while the combustion efficiency of the fuel is greatly improved; in the injection stage (Ma0-1.6), a contraction flow channel is formed, which conforms to the flow law of the subsonic airflow in the engine. On the one hand, the contraction flow channel assists the gas congestion and improves the engine momentum thrust; on the other hand, the contraction flow channel greatly improves the fuel in the combustion chamber. The mixing efficiency and combustion efficiency with air, thereby generating a higher combustion chamber pressure, greatly improving the combustion chamber thrust and forming a thrust gain; forming a convergent-divergent flow channel in the sub-combustion mode (Ma2-8), and controlling the throat height to make the airflow congested at the throat for different incoming flow conditions. On the one hand, the geometric throat adjustment technology effectively controls the combustion heat release area, shortens the engine length, and the throttling effect of the geometric throat is beneficial to the combustion heat release of the fuel; on the other hand, the geometric throat technology greatly improves the thrust and specific impulse performance of the sub-combustion mode; and improves the engine intake and overall stability. The present invention has a compact structure, flexible and reliable switching, good sealing performance, and is easy to integrate and maintain. It not only solves the problem of matching and balancing the intake and combustion chamber flow profiles of the RBCC engine at full speed, but also significantly improves the full-speed performance of the RBCC engine, and has a strong promotion and application value;

[0012] The bidirectionally adjustable geometric throat device provided by the present invention has the following characteristics: in the ejection mode, the rotating cylinders of the first and second electromagnetic push rod mechanisms extend into the limiting holes of the throat block, thereby locking the throat block; the rotating cylinders of the third and fourth electromagnetic push rod mechanisms retract, that is, disengage from the limiting holes of the throat block, and retract to cut off the connection with the throat block; the driving device is actuated to extend the push rod, pushing the throat block, thereby causing the right end of the throat block to sink, while the left end remains in a normal state, thereby forming a contraction-type flow channel;

[0013] When in the sub-combustion mode, the push rod in the fifth electromagnetic push rod mechanism is actuated, and the push rod retracts to drive the throat block back to the reference position; then the third electromagnetic push rod mechanism and the fourth electromagnetic push rod mechanism extend into the limiting hole of the throat block, thereby jamming the throat block; and the rotating cylinders of the first electromagnetic push rod mechanism and the second electromagnetic push rod mechanism are disengaged from the limiting hole of the throat block, and release the throat block, thereby causing the push rod of the drive device to be actuated, and the push rod pushes the left end of the throat block to sink and form an expansion type flow channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the overall structure of the geometric throat device according to an embodiment of the present invention.

[0015] Figure 2 It is a front view of a geometric throat device according to an embodiment of the present invention.

[0016] Figure 3 1 is a top view of a geometric throat device according to an embodiment of the present invention.

[0017] Figure 4 yes Figure 2 EE cross-sectional view.

[0018] Figure 5 yes Figure 3 FF cross-sectional view.

[0019] Figure 6 yes Figure 2 HH cross-sectional view.

[0020] Figure 7 It is a schematic diagram of the throat block structure of an embodiment of the present invention.

[0021] Figure 8 4 is a top view of the first electromagnetic push rod mechanism according to an embodiment of the present invention.

[0022] Figure 9 yes Figure 8 AA cross-sectional view.

[0023] Figure 10 It is a schematic diagram of the state when the throat block is at the reference position.

[0024] Figure 11 It is a schematic diagram of the throat blockage state under the ejection mode.

[0025] In the figure, 100. Geometric throat section, 200. Throat block, 300. Switching mechanism, 400. Driving device;

[0026] 101. Front side wall, 102. Lower base, 103. Rear side wall, 104. Left flange connection section, 105. Right flange connection section, 106. Left sealing cover, 107. Right sealing cover;

[0027] 201. First vertical side panel, 202. Second vertical side panel, 203. Curved panel, 204. Bottom panel;

[0028] 301. First electromagnetic push rod mechanism, 302. Second electromagnetic push rod mechanism, 303. Third electromagnetic push rod mechanism, 304. Fourth electromagnetic push rod mechanism, 305. Oil-free bushing;

[0029] 3011. Rotating cylinder, 3012. Driving screw, 3013. First reduction gearbox, 3014. Driving motor, 3015. Limiting ring; 3016. Limiting cylinder;

[0030] 3021. Second rotating cylinder, 3031. Third rotating cylinder, 3041. Fourth rotating cylinder;

[0031] 401. Fifth electromagnetic push rod mechanism, 402. Left support plate, 403. Right support plate, 404. Horizontal mounting plate, 405. First hinge connection base, 406. Second hinge connection base;

[0032] 4011. Push rod, 4012. Second lead screw, 4013. Second reduction gearbox, 4014. Second motor. DETAILED DESCRIPTION

[0033] like Figures 1 to 6 As shown, an embodiment of the present invention provides a bidirectionally adjustable geometric throat for a rocket-based combined cycle engine, including a geometric throat section 100, a throat block 200, and a switching mechanism 300.

[0034] The cavity formed by the geometric throat section 100 forms part of the internal flow path of the engine combustion chamber. Its smooth transition and excellent sealing ensure smooth airflow. Throat block 200, located above the interior of the geometric throat section 100, is a block-shaped mechanism that directly alters the flow path's shape. The switching mechanism 300 rotates throat block 200 by adjusting the telescopic state of each rotating cylinder, thereby changing its posture and switching the internal flow path of the geometric throat section 100 between contraction and expansion.

[0035] The geometric throat section 100 is a shell structure with openings on the left, right and top. The shell structure includes a front side wall panel 101, a rear side wall panel 103 and a lower base plate 102. The front side wall panel 101 and the rear side wall panel 103 are arranged in parallel. The front side wall panel 101 and the rear side wall panel 103 are respectively fixed vertically on both sides of the upper surface of the lower base plate 102. The front side wall panel 101, the rear side wall panel 103 and the lower base plate 102 are fixedly connected by fastening screws.

[0036] Preferably, the geometric throat section 100 includes a front side wall panel 101, a rear side wall panel 103 and a lower base plate 102, wherein the front side wall panel 101 and the rear side wall panel 103 are arranged in parallel, and the front side wall panel 101 and the rear side wall panel 103 are vertically fixed on both sides of the upper surface of the lower base plate 102 respectively.

[0037] In some examples, a left flange connection section 104 is fixedly connected to the left opening of the geometric throat section 100 for fixed connection to the combustion chamber section; a right flange connection section 105 is fixedly connected to the right opening of the geometric throat section 100 for fixed connection to the tail nozzle section.

[0038] In some examples, a first sealing groove is defined at the upper end of the connection between the left flange connection section 104 and the front and rear sidewall panels 101 and 103, into which a left sealing cover plate 106 is installed. A second sealing groove is defined at the upper end of the connection between the right flange connection section 105 and the front and rear sidewall panels 101 and 103, into which a right sealing cover plate 107 is installed. The left and right sealing cover plates 106 and 107 together ensure a tight seal during movement of the throat block 200.

[0039] The throat blocking block 200 includes: a bottom plate 204 , a first vertical side plate 201 , a second vertical side plate 202 , and an arc-shaped plate 203 .

[0040] The bottom plate 204 is horizontal and located at the upper opening of the geometric throat section 100 , and is loosely fitted with the upper opening of the geometric throat section 100 .

[0041] The first vertical side panel 201 is fan-shaped and vertically arranged. The first vertical side panel 201 is located in front of the bottom panel 204 , and a straight edge of the first vertical side panel 201 is fixedly connected to the front of the bottom panel 204 .

[0042] The second vertical side panel 202 is fan-shaped and vertically arranged relative to the first vertical side panel 201 . The second vertical side panel 202 is located on the rear side of the bottom panel 204 , and a straight edge of the second vertical side panel 202 is fixedly connected to the rear side of the bottom panel 204 .

[0043] The lower end of the arc plate 203 is fixedly connected to the left end of the bottom plate 204, the upper end of the arc plate 203 extends upward, and the front and rear ends of the arc plate 203 are respectively fixedly connected to the arc edges of the first vertical side plate 201 and the second vertical side plate 202, thereby forming a throat block 200 with an open top and a hollow interior.

[0044] In some examples, two circular grooves are respectively provided on the first vertical side plate 201 and the second vertical side plate 202, and the positions and radial dimensions of the circular grooves correspond to the through holes on the geometric throat section 100. Preferably, a through hole is respectively provided on the left and right ends of the first vertical side plate 201, that is, a through hole is provided on the end of the first vertical side plate 201 close to the combustion chamber, and a through hole is also provided on the end close to the tail nozzle section. Similarly, a through hole is respectively provided on the left and right ends of the second vertical side plate 202, that is, a through hole is provided on the end of the second vertical side plate 202 close to the combustion chamber, and a through hole is also provided on the end close to the tail nozzle section. These through holes are used for the rotating cylinder of the switching mechanism 300 to extend into. In addition, an oil-free bushing 305 is placed in each of these through holes to achieve the translational movement of each rotating cylinder in the hole.

[0045] The switching mechanism 300 includes a first electromagnetic push rod mechanism 301, a second electromagnetic push rod mechanism 302, a third electromagnetic push rod mechanism 303, and a fourth electromagnetic push rod mechanism 304. The first electromagnetic push rod mechanism 301 and the third electromagnetic push rod mechanism 303 are respectively fixedly connected to the front side wall plate 101, and the second electromagnetic push rod mechanism 302 and the fourth electromagnetic push rod mechanism 304 are respectively fixedly connected to the rear side wall plate 103. Preferably, the first electromagnetic push rod mechanism 301 and the second electromagnetic push rod mechanism 302 are disposed near the combustion chamber section, and the third electromagnetic push rod mechanism 303 and the fourth electromagnetic push rod mechanism 304 are disposed near the tail nozzle section.

[0046] In some examples, reference Figures 8 and 9 The first electromagnetic push rod mechanism 301 , the second electromagnetic push rod mechanism 302 , the third electromagnetic push rod mechanism 303 and the fourth electromagnetic push rod mechanism 304 all include: a driving motor 3014 , a rotating cylinder 3011 and a limiting cylinder 3016 .

[0047] The driving motor 3014 is fixed to the outer wall of the front side wall panel 101 or the rear side wall panel 103 through a fixing frame; the output end of the driving motor 3014 is connected to the driving screw 3012 through the first reduction gear box 3013 installed on the fixing frame; the driving screw 3012 extends through the through hole opened on the front side wall panel 101 or the rear side wall panel 103 to the front side or rear side of the throat block 200; the driving screw 3012 is used to move back and forth under the drive of the driving motor 3014.

[0048] The rotating cylinder 3011 is sleeved on the outer periphery of the driving screw 3012, and the inner wall of the rotating cylinder 3011 is threadedly connected to the outer wall of the driving screw 3012. The rotating cylinder 3011 is used to move back and forth under the drive of the driving screw 3012, and then extend into or disengage from the limiting hole opened in the first vertical side plate 201 or the second vertical side plate 202, thereby clamping or loosening the throat block 200; a sliding groove is opened on the outer wall surface of the rotating cylinder 3011 along the front-to-back direction, and the sliding groove is opened in the part away from the throat block 200.

[0049] The limiting cylinder 3016 is sleeved on the outer periphery of the rotating cylinder 3011, one end of the limiting cylinder 3016 is fixed on the first reduction gear box 3013, and the other end of the limiting cylinder 3016 extends toward the throat block 200. The limiting cylinder 3016 is close to the inner wall of one end of the throat block 200 and is fixedly connected to the limiting ring 3015 around it. The limiting ring 3015 is used to extend into the sliding groove of the rotating cylinder 3011, thereby clamping the rotating cylinder 3011 and preventing the rotating cylinder 3011 from rotating. The limiting ring 3015 is also used to limit the amplitude of the forward and backward movement of the rotating cylinder 3011.

[0050] Preferably, grooves may be formed on both sides of the outer wall of the rotating cylinder 3011 , so that the limiting ring 3015 can better limit the rotation of the rotating cylinder 3011 without affecting the forward and backward movement of the rotating cylinder 3011 .

[0051] The rotating cylinder 3011 is located in the oil-free bushing 305 in the through hole opened in the front side wall plate 101. When the driving motor 3014 is working, the appropriate rotation speed is transmitted to the driving screw 3012 through the first reduction gear box 3013. Since the limiting cylinder 3016 limits the rotation of the rotating cylinder 3011, the rotation of the driving screw 3012 will drive the rotating cylinder 3011 to move forward and backward along the axial direction.

[0052] Specifically, when the driving motor 3014 rotates forward, the rotating drum 3011 will move outwardly away from the first reduction gear box 3013 along the axial direction, and when the driving motor 3014 rotates reversely, the rotating drum 3011 will move inwardly along the axial direction.

[0053] In some examples, the second electromagnetic push rod mechanism 302, the third electromagnetic push rod mechanism 303, and the fourth electromagnetic push rod mechanism 304 have the same structure as the first electromagnetic push rod mechanism 301, wherein the second rotating cylinder 3021 of the second electromagnetic push rod mechanism 302 is located in the oil-free bushing 305 in the corresponding through hole on the rear side wall plate 103; the third rotating cylinder 3031 of the second electromagnetic push rod mechanism 302 is located in the oil-free bushing 305 in the corresponding through hole on the front side wall plate 101, and the fourth rotating cylinder 3041 of the fourth electromagnetic push rod mechanism 304 is located in the oil-free bushing 305 in the corresponding through hole on the rear side wall plate 103.

[0054] In some examples, a shell or a fixing frame is provided on the outside of the first electromagnetic push rod mechanism 301, the second electromagnetic push rod mechanism 302, the third electromagnetic push rod mechanism 303 and the fourth electromagnetic push rod mechanism 304, wherein the first reduction gear box 3013 and the drive motor 3014 of the first electromagnetic push rod mechanism 301 are fixed inside the shell of the first electromagnetic push rod mechanism 301, and the shell or the fixing frame of the first electromagnetic push rod mechanism 301 is fixedly connected to the corresponding front side wall plate 101 through a flange structure.

[0055] The present invention also includes a driving device 400, which is rotatably connected to the throat block 200 and is used to drive the left end or the right end of the throat block 200 to sink, thereby switching the internal flow channel of the geometric throat section 100 between contraction and expansion.

[0056] The drive device 400 includes a fifth electromagnetic push rod mechanism 401, a left support plate 402, a right support plate 403, and a horizontal mounting plate 404. The left and right support plates 402 and 403 are vertically fixed to the tops of the left and right flange connection sections 104 and 105, respectively. The horizontal mounting plate 404 is horizontally fixed between the upper ends of the left and right support plates 402 and 403. The left and right support plates 402, 403, and the horizontal mounting plate 404 form a stable support structure for connecting the fifth electromagnetic push rod mechanism 401. The upper end of the fifth electromagnetic push rod mechanism 401 is connected to a second hinge connection base 406 fixed to the lower surface of the horizontal mounting plate 404. The lower end of the fifth electromagnetic push rod mechanism 401 is rotatably connected to the middle portion of the throat block 200 via a first hinge connection base 405. The fifth electromagnetic push rod mechanism 401 is used to drive the throat block 200 for rotation.

[0057] In some examples, a first hinge connection seat 405 is fixedly provided at the center position of the upper surface of the bottom plate of the throat block 200 to achieve the hinge connection between the throat block 200 and the driving device 400.

[0058] In some examples, the fifth electromagnetic push rod mechanism 401 includes a second motor 4014 , a second reduction gear box 4013 , a second lead screw 4012 , and a push rod 4011 .

[0059] The second reduction gearbox 4013 is rotatably connected to the horizontal mounting plate 404 through the second hinge connection seat 406; the second motor 4014 is fixed on the outer surface of the second reduction gearbox 4013, and the output end of the second motor 4014 is transmission-connected to the input end of the second reduction gearbox 4013; one end of the second lead screw 4012 is transmission-connected to the output end of the second reduction gearbox 4013; the second motor 4014 decelerates the rotational force through the second reduction gearbox 4013 and transmits it to the second lead screw 4012.

[0060] The upper end of the push rod 4011 is connected to the other end of the second screw 4012 through a threaded connection, and the second screw 4012 is coaxial with the push rod 4011; the lower end of the push rod 4011 is rotatably connected to the throat block 200 through the first hinge connection seat 405; the push rod 4011 converts the rotational force transmitted by the second screw 4012 into a vertical force through a threaded connection to drive the throat block 200 to move.

[0061] Preferably, the second motor 4014 is in transmission connection with the second reduction gearbox 4013, and the housing of the second motor 4014 is fixed to the outer surface of the second reduction gearbox 4013. The second reduction gearbox 4013 is rotationally connected to the horizontal mounting plate 404. The second lead screw 4012 is in transmission connection with the second reduction gearbox 4013, and the end of the second lead screw 4012 away from the second reduction gearbox 4013 is threadedly connected to the push rod 4011. The push rod 4011 is rotationally connected to the horizontal mounting plate 404 via the second hinge connection seat 406. In the fifth electromagnetic push rod mechanism 401, the second motor 4014 provides power, which transmits the reduced torque to the second lead screw 4012 via the second reduction gearbox 4013. The push rod 4011 converts the rotational force into vertical motion through the threads, pushing / pulling the throat block 200.

[0062] In some examples, U-shaped connection structures are provided at the upper and lower ends of the fifth electromagnetic push rod mechanism 401, wherein the upper U-shaped connection structure is fixed to the upper end of the second reduction gear box 4013, and is rotatably connected to the horizontal mounting plate 404 through the second hinge connection seat 406; the lower U-shaped connection structure is fixed to the lower end of the push rod 4011, and is rotatably connected to the throat block 200 through the first hinge connection seat 405.

[0063] In some examples, Figure 10 This is a schematic diagram of the throat block 200 at the reference position. Figure 10 In the reference position, the throat block 200 is in a horizontal state, and the air flow rate in the internal flow channel of the geometric throat section 100 is constant.

[0064] Reference Figure 11 In the ejection mode, the throat block 200 needs to remain horizontal at its left end and sink at its right end, forming a contracting flow channel. At this point, the rotating cylinders of the first and second electromagnetic push rod mechanisms 301, 302 in the switching mechanism 300 extend into the limiting holes of the throat block 200, thereby locking the throat block 200. The third rotating cylinder 3031 of the third electromagnetic push rod mechanism 303 and the fourth rotating cylinder 3041 of the fourth electromagnetic push rod mechanism 304 retract into the front side wall 101 and rear side wall 103, respectively, severing their connection with the throat block 200. At this point, the first rotating cylinder 3011 and the second rotating cylinder 3021 serve as the rotation axis of the throat block 200. Then, the fifth electromagnetic push rod mechanism 401 of the drive device 400 is actuated to extend the push rod 4011, pushing the throat block 200 to rotate, thereby forming a contracting flow channel.

[0065] When the ground zero-speed ejection stage and the incoming flow are 0.4Ma, the expansion ratio of the outlet cross-section of the flow channel contraction section is 1.6. The expansion ratio is the ratio of the outlet cross-section area of the contraction section to the throat area of the engine inlet duct. If the throat area of the inlet duct is 0.01m2 According to the expansion ratio of 1.6, the cross-sectional area of the contraction section outlet is calculated to be 0.016m 2 Given that the flow channel width formed by the device is 0.16m, the throat height, i.e., the height H1 between the lowest end of the throat block 200 and the lower base plate 102, is 0.1m. Similarly, the corresponding throat height H1 can be calculated based on the expansion ratio requirements of different incoming flows.

[0066] Figure 5 This is a schematic diagram of the throat block 200 in the sub-combustion mode. Figure 5 When in the sub-combustion mode, the left end of the throat block 200 needs to sink and the right end needs to remain horizontal to form an expansion flow channel.

[0067] First, the fifth electromagnetic push rod mechanism 401 in the drive device 400 is actuated, and the push rod 4011 retracts, driving the throat block 200 back to its reference position. The third rotating cylinder 3031 of the third electromagnetic push rod mechanism 303 and the fourth rotating cylinder 3041 of the fourth electromagnetic push rod mechanism 304 then extend into the retaining hole of the throat block 200, serving as the rotation axis of the throat block 200. The first rotating cylinder 3011 and the second rotating cylinder 3021 then retract, retracting into the through-holes of the front side wall 101 and rear side wall 103, respectively, disconnecting from the throat block 200. Finally, the push rod 4011 of the drive device 400 is actuated again, pushing the throat block 200 to rotate and form an expansion-type flow channel.

[0068] When the incoming flow is 3Ma and the expansion ratio of the throat section is 2.3, the throat area of the inlet is assumed to be 0.01m 2 The expansion ratio is 2.3, and the cross-sectional area of the contraction section outlet is calculated to be 0.023m 2 Given that the flow channel width formed by this device is 0.16m, the throat height, i.e., the height H2 between the lowest end of the throat block 200 and the lower base plate 102, is 0.143m. Similarly, the corresponding throat height H2 can be calculated based on the expansion ratio requirements of different incoming flows.

[0069] Preferably, from Ma0 to Ma0.8, the right end of the throat sinks, and the throat expansion ratio is 1.85; from Ma1.2 to Ma1.6, the right end of the throat sinks, and the throat expansion ratio is 1.90; from Ma1.6 to Ma2, the throat is in a reference state and remains horizontal. At Ma3, the left end of the geometric throat sinks, and the throat expansion ratio is 2.5; at Ma4, the left end of the geometric throat sinks, and the throat expansion ratio is 2.0; from Ma5 to Ma6, the left end of the geometric throat sinks, and the throat expansion ratio is 1.6; from Ma7 to Ma8, the left end of the geometric throat sinks, and the throat expansion ratio is 1.4.

Claims

1. A bidirectionally adjustable geometric throat for a rocket-based combined cycle engine, characterized in that: include: A geometric throat section (100), the geometric throat section (100) is a shell structure with openings on the left, right and top sides, the left opening of the geometric throat section (100) is fixedly connected to the combustion chamber section, and the right opening of the geometric throat section (100) is fixedly connected to the tail nozzle section; the interior of the shell of the geometric throat section (100) is a gas flow channel of the engine combustion chamber; A throat block (200), wherein the throat block (200) is arranged at the upper opening of the geometric throat section (100), and the internal flow channel shape of the geometric throat section (100) is adjusted by adjusting the posture of the throat block (200); A switching mechanism (300) is fixed on the geometric throat section (100), and each rotating cylinder of the switching mechanism (300) penetrates the shell of the geometric throat section (100) and clamps or releases the throat block (200); the switching mechanism (300) adjusts the telescopic state of each rotating cylinder to rotate the throat block (200) to change the posture of the throat block (200), thereby switching the internal flow channel of the geometric throat section (100) between contraction and expansion.

2. The bidirectionally adjustable geometric throat for a rocket-based combined cycle engine according to claim 1, characterized in that: The geometric throat section (100) comprises a front side wall plate (101), a rear side wall plate (103) and a lower base plate (102), wherein the front side wall plate (101) and the rear side wall plate (103) are arranged in parallel, and the front side wall plate (101) and the rear side wall plate (103) are respectively fixed vertically on both sides of the upper surface of the lower base plate (102).

3. The bidirectionally adjustable geometric throat for a rocket-based combined cycle engine according to claim 2, characterized in that: The left opening of the geometric throat section (100) is fixedly connected to the combustion chamber section via a left flange connection section (104), and the right opening of the geometric throat section (100) is fixedly connected to the tail nozzle section via a right flange connection section (105); A first sealing groove is provided at the upper end of the connection between the left flange connection section (104) and the front side wall plate (101) and the rear side wall plate (103), and a left sealing cover plate (106) is installed in the first sealing groove; a second sealing groove is provided at the upper end of the connection between the right flange connection section (105) and the front side wall plate (101) and the rear side wall plate (103), and a right sealing cover plate (107) is installed in the second sealing groove; the left sealing cover plate (106) and the right sealing cover plate (107) are respectively matched with the throat block (200) to ensure the sealing performance of the throat block (200) during movement.

4. The bidirectionally adjustable geometric throat for a rocket-based combined cycle engine according to claim 2, characterized in that: The throat block (200) comprises: The bottom plate (204) is horizontal and located at the upper opening of the geometric throat section (100), and is in clearance fit with the upper opening of the geometric throat section (100); a first vertical side panel (201), the first vertical side panel (201) being fan-shaped and vertically arranged, the first vertical side panel (201) being located in front of the bottom panel (204), and a straight edge of the first vertical side panel (201) being fixedly connected to the front of the bottom panel (204); a second vertical side panel (202), the second vertical side panel (202) being fan-shaped and arranged vertically relative to the first vertical side panel (201), the second vertical side panel (202) being located on the rear side of the bottom panel (204), and a straight edge of the second vertical side panel (202) being fixedly connected to the rear side of the bottom panel (204); The arc-shaped plate (203) has its lower end fixedly connected to the left end of the bottom plate (204), its upper end extends upward, and its front and rear ends are respectively fixedly connected to the arc-shaped edges of the first vertical side plate (201) and the second vertical side plate (202), thereby forming a throat block (200) with an open top and a hollow interior.

5. The bidirectionally adjustable geometric throat for a rocket-based combined cycle engine according to claim 2, characterized in that: The switching mechanism (300) comprises a first electromagnetic push rod mechanism (301), a second electromagnetic push rod mechanism (302), a third electromagnetic push rod mechanism (303) and a fourth electromagnetic push rod mechanism (304), wherein the first electromagnetic push rod mechanism (301) and the third electromagnetic push rod mechanism (303) are respectively fixedly connected to the front side wall plate (101), and the second electromagnetic push rod mechanism (302) and the fourth electromagnetic push rod mechanism (304) are respectively fixedly connected to the rear side wall plate (103); the first electromagnetic push rod mechanism (301) and the second electromagnetic push rod mechanism (302) are arranged near the combustion chamber section, and the third electromagnetic push rod mechanism (303) and the fourth electromagnetic push rod mechanism (304) are arranged near the tail nozzle section.

6. The bidirectionally adjustable geometric throat for a rocket-based combined cycle engine according to claim 5, characterized in that: The first electromagnetic push rod mechanism (301), the second electromagnetic push rod mechanism (302), the third electromagnetic push rod mechanism (303) and the fourth electromagnetic push rod mechanism (304) all include: A driving motor (3014) is fixed to the outer wall of the front side wall plate (101) or the rear side wall plate (103) via a fixing frame; an output end of the driving motor (3014) is connected to a driving screw (3012) via a first reduction gear box (3013) mounted on the fixing frame; the driving screw (3012) extends through a through hole provided on the front side wall plate (101) or the rear side wall plate (103) toward the front side or the rear side of the throat block (200); the driving screw (3012) is used to move forward and backward under the drive of the driving motor (3014); a rotating cylinder (3011), the rotating cylinder (3011) being sleeved on the periphery of the driving screw (3012), the inner wall of the rotating cylinder (3011) being threadedly connected to the outer wall of the driving screw (3012), the rotating cylinder (3011) being used to move forward and backward under the drive of the driving screw (3012), thereby extending into or disengaging from a limiting hole provided in the first vertical side plate (201) or the second vertical side plate (202), thereby clamping or releasing the throat block (200); a sliding groove is provided on the outer wall surface of the rotating cylinder (3011) along the front-to-back direction, and the sliding groove is provided at a portion away from the throat block (200); A limiting cylinder (3016) is sleeved on the periphery of the rotating cylinder (3011), one end of the limiting cylinder (3016) is fixed on the first reduction gear box (3013), and the other end of the limiting cylinder (3016) extends toward the throat block (200). A limiting ring (3015) is fixedly connected to the inner wall of one end of the limiting cylinder (3016) close to the throat block (200) and around the limiting ring. The limiting ring (3015) is used to extend into the sliding groove of the rotating cylinder (3011) to clamp the rotating cylinder (3011) and prevent the rotating cylinder (3011) from rotating. The limiting ring (3015) is also used to limit the amplitude of the forward and backward movement of the rotating cylinder (3011).

7. The bidirectionally adjustable geometric throat for a rocket-based combined cycle engine according to claim 3, characterized in that: Also includes: A driving device (400) is rotatably connected to the throat block (200) and is used to drive the left end or the right end of the throat block (200) to sink, thereby switching the internal flow channel of the geometric throat section (100) between contraction and expansion.

8. The bidirectionally adjustable geometric throat for a rocket-based combined cycle engine according to claim 7, characterized in that: The driving device (400) comprises: a fifth electromagnetic push rod mechanism (401), a left support plate (402), a right support plate (403) and a horizontal mounting plate (404), wherein: The left support plate (402) and the right support plate (403) are respectively vertically fixed on the top of the left flange connection section (104) and the right flange connection section (105), and the horizontal mounting plate (404) is horizontally fixed between the upper ends of the left support plate (402) and the right support plate (403); the upper end of the fifth electromagnetic push rod mechanism (401) is rotatably connected to the horizontal mounting plate (404) through a second hinge connection seat (406), and the lower end of the fifth electromagnetic push rod mechanism (401) is rotatably connected to the middle part of the throat block (200) through a first hinge connection seat (405); the fifth electromagnetic push rod mechanism (401) is used to push the throat block (200) to rotate.

9. The bidirectionally adjustable geometric throat for a rocket-based combined cycle engine according to claim 8, characterized in that: The fifth electromagnetic push rod mechanism (401) comprises: a second reduction gearbox (4013), the second reduction gearbox (4013) being rotatably connected to the horizontal mounting plate (404) via a second hinge connection seat (406); a second motor (4014), the second motor (4014) being fixed to the outer surface of the second reduction gearbox (4013), and the output end of the second motor (4014) being transmission-connected to the input end of the second reduction gearbox (4013); a second lead screw (4012), one end of the second lead screw (4012) being transmission-connected to the output end of the second reduction gear box (4013); the second motor (4014) transmits the rotational force to the second lead screw (4012) after decelerating the rotational force through the second reduction gear box (4013); A push rod (4011), the upper end of the push rod (4011) is connected to the other end of the second lead screw (4012) through a thread, and the second lead screw (4012) and the push rod (4011) are coaxial; the lower end of the push rod (4011) is rotatably connected to the throat block (200) through a first hinge connection seat (405); the push rod (4011) converts the rotational force transmitted by the second lead screw (4012) into a vertical force through the threaded connection to drive the throat block (200) to move.

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